/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.storm.metric.api;

/**
 * Produces metrics
 */
public interface IMetric {
    /**
     * @return an object that will be sent sent to {@link IMetricsConsumer#handleDataPoints(org.apache.storm.metric.api.IMetricsConsumer.TaskInfo, java.util.Collection)}.
     * If null is returned nothing will be sent.
     * If this value can be reset, like with a counter, a side effect of calling this should be that the value is reset.
     */
    public Object getValueAndReset();
}
